The non-inferiority of piperonyl-butoxide Yorkool G3 insecticide-treated nets compared to Olyset®Plus measured by Anopheles arabiensis mortality in experimental huts in Tanzania.

Background: Non-inferiority trials are recommended by the World Health Organization (WHO) to demonstrate that health products show comparable efficacy to that of existing standard of care. As part of the WHO Global Malaria Programme (GMP) process of assessment of malaria vector control products, a second-in-class insecticide-treated net (ITN) must be shown to be non-inferior to a first-in-class product based on mosquito mortality. The public health impact of the first-in-class pyrethroid-piperonyl butoxide (PBO) ITN, Olyset Plus, has been demonstrated in epidemiological trials in areas with insecticide-resistant mosquitoes, but there is a need to determine the efficacy of other pyrethroid-PBO nets to ensure timely market availability of nets in order to increase access to ITNs.

Additional blood meals increase sporozoite infection in Anopheles mosquitoes but not Plasmodium falciparum genetic diversity.

The availability of nutrients from mosquito blood meals accelerates the development of Plasmodium falciparum laboratory strains in artificially infected Anopheles gambiae mosquitoes. The impact of multiple blood meals on the number of P. falciparum genotypes developing from polyclonal natural human malaria infections (field-isolates) remains unexplored.

Time of exposure and assessment influence the mortality induced by insecticides against metabolic resistant mosquitoes.

Background: Increasing metabolic resistance in malaria vector mosquitoes resulted in the development of insecticide-treated nets (ITNs) with active ingredients (AI) that target them. Bioassays that accurately measure the mortality induced by these AIs on ITNs are needed. Mosquito metabolic enzyme expression follows a circadian rhythm.

Factors associated with malaria infection among children after distribution of PBO-pyrethroid synergist-treated nets and indoor residual spraying in north-western Tanzania.

Background: After a decade of successful control, malaria is on the rise again. The prevalence of malaria in Tanzania has increased from 7% in 2017 to 8% in 2022 and reached 18% in Kagera region in the North West of Tanzania. Malaria vectors in Muleba district Kagera have high level of pyrethroid resistance.

Malaria rapid diagnostic tests reliably detect asymptomatic Plasmodium falciparum infections in school-aged children that are infectious to mosquitoes.

Background: Asymptomatic malaria infections (Plasmodium falciparum) are common in school-aged children and represent a disease transmission reservoir as they are potentially infectious to mosquitoes. To detect and treat such infections, convenient, rapid and reliable diagnostic tools are needed. In this study, malaria rapid diagnostic tests (mRDT), light microscopy (LM) and quantitative polymerase chain reaction (qPCR) were used to evaluate their performance detecting asymptomatic malaria infections that are infectious to mosquitoes.

Assessing the variability in experimental hut trials evaluating insecticide-treated nets against malaria vectors.

Experimental hut trials (EHTs) are used to evaluate indoor vector control interventions against malaria vectors in a controlled setting. The level of variability present in the assay will influence whether a given study is well powered to answer the research question being considered. We utilised disaggregated data from 15 previous EHTs to gain insight into the behaviour typically observed.